Martyn's Z4M Coupe

Martyn · Post by **Martyn** » Sat May 06, 2023 8:31 am

Made some good progress yesterday, I got the shift wires run to the clock spring where I re-pinned the stock connector. I fitted dupont connectors to the horn and shift paddle connections so it's plug and play.

I also configured my Plex USDM to display DCT related status such as gear, drivelogic mode etc

Something I'd overlooked when deciding to do the conversion was how the reverse light would be triggered, luckily it was pretty easy to sort. I used a male connector to plug directly into the reverse switch connector, then ran that to a small relay and then to a spare output on the MaxxECU. I configured the MaxxECU to ground the output when R is selected. This closes the contacts on the relay and the reverse lights and PDC spring to life.

I also made up the gearbox oil cooler lines with AN fittings, mounted the F8x M3 DCT thermostat and filled the box with gearbox oil.

Lastly I ran the engine and checked that the starter engaged the new flywheel OK and that I could engage gears, thankfully I could engage R, 1st and 2nd without any issue, I couldn't get any higher gears due to the lack of propshaft (no wheel speed reported obviously).

Wassup · Post by **Wassup** » Tue May 09, 2023 8:51 pm

This is going to be the nuts...dct z4m

Ed Doe · Post by **Ed Doe** » Tue May 09, 2023 9:38 pm

Wassup wrote: ↑Tue May 09, 2023 8:51 pm This is going to be the nuts...dct z4m

*ahem* dct SUPERCHARGED z4m! Even more nuts!

Martyn · Post by **Martyn** » Thu May 11, 2023 12:15 pm

A few more small updates while I wait for the prop.

A wanted a clean location for the drivelogic button, so I drew up an ashtray insert in Fusion360 and printed a panel to sit in the ashtray.

I also filled the gearbox properly after temporarily fitting the exhaust. I had to clearance one of the lugs on the back of the gearbox to make the exhaust fit but there was plenty of 'meat' there to take off without causing any issue.

F8x DCT Thermostat mounted securely. Exhaust the welding on the AN fittings, it wasn't my finest work!

DCT oil cooler mounted above the main engine cooler.

Lastly I swapped out the front springs on my BCs from 8kg/mm to 6kg/mm.

robear · Post by **robear** » Thu May 11, 2023 1:41 pm

Very cool DCT swap!

How are you liking the BC Coilovers for normal driving comfort and which spring rates did you choose for the rear? I'm considering these coilovers for daily use.

Martyn · Post by **Martyn** » Thu May 11, 2023 3:25 pm

Thanks.

I'm not convinced on the 8Kg springs hence trying the 6Kg ones. The rears are currently 10Kg, I've tried 12Kg too but prefer the 10Kg so far. The ride is great at speed, but feels a little harsh at lower speeds, hopefully the 6Kg ones should help a bit with this.

Another minor update, but I removed the clutch pedal today

Excuse the state of the footwell! The master cylinder has been disconnected from the bottle but I've left it bolted up to the pedal framework, in case I ever need to revert back to manual.

I've disconnected the slave at the junction for the hardline and drained it down.

Hopefully the propshaft should be ready for the weekend

Martyn · Post by **Martyn** » Thu May 11, 2023 4:11 pm

Oh, my engineering guy just sent me an update on the propshaft.

He's machined a sleeve to insert into the 2 halves of the prop.

He'll face the ends of the propshaft and yoke, set the length then insert and weld.

inkey$ · Post by **inkey$** » Thu May 11, 2023 4:36 pm

How did I miss this thread?! incredible work, OP. She's going to be a rare beast for sure!

robear · Post by **robear** » Thu May 11, 2023 7:07 pm

I didn't know that they modify propshafts using a coupler like that. Now it makes sense how they keep the modified propshaft straight.

I believe the BC's come with 8kg/mm rear and 6kg/mm front spring. I'll probably give those a try before changing for a higher rear spring rate.

I just read the whole build and I noticed that you used to have the Geoff Steel CSL intake on the car. I'm going the carbon intake route and I wanted to ask if the .stl is available for the snorkel piece?

Looking forward to more DCT updates

Beedub · Post by **Beedub** » Thu May 11, 2023 7:26 pm

absolutely incredible and THE best z4m thread . EVER.... bar NONE. well done , a total credit to the z4m community.

curvature · Post by **curvature** » Thu May 11, 2023 7:57 pm

Great reading and I am in awe of your skills.

Please do keep this thread updated.

Martyn · Post by **Martyn** » Thu May 11, 2023 10:04 pm

Thank you!

Well, my friend dropped the finished prop round after dinner so I did my chores and cracked straight on.

I gave the end of the prop a quick dusting with some black paint to cover the welds, then got it bolted up!

Everything is now back together apart from the small cover that covers the gearbox, which no longer fits so I may modify that, or just leave it off.

First testing tomorrow, fingers are crossed!

Beedub · Post by **Beedub** » Fri May 12, 2023 6:51 am

i like seeing the gearbox sump.... looks so cool! please make videos, with a blower this will actually be a complete supercar slayer!

Martyn · Post by **Martyn** » Fri May 12, 2023 11:28 am

It's back on the deck and sporting new 'lows' due to the softer front springs and the lardy DCT gearbox so I need to sort that out!

The good news is it moves!

Take up is super smooth after a few tweaks.

It gets down the road and grabs gears without too much drama but it's gonna need a few hours of tweaking to get the estimated torque table for the DCT dialled in. Once i've done that I'll try and find the suction mount for the GoPro.

1536Z4 · Post by **1536Z4** » Fri May 12, 2023 5:24 pm

Martyn wrote: ↑Fri May 12, 2023 11:28 am The good news is it moves!

What a result

Not that I ever doubted it would work . Well done Martyn

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